1. Field of the Invention
The invention generally relates to an illumination module for a liquid crystal display (LCD) device.
2. Prior Art
In general, an LCD device has the advantages of thinness, light weight, and low power consumption. For this reason, LCD devices are widely utilized in various types of electronic equipment, from pocket calculators to large-scale office automation equipment.
It is well known that the larger an LCD is, the more linear light sources must be provided therein to brightly light it. It is desirable that manufacturing of the large-scale LCDs be efficient, even though numerous light sources need to be incorporated into the LCDs. Each linear light source is generally a Cold Cathode Fluorescence Lamp (CCFL).
U.S. Pat. No. 6,330,150 issued to Soon-Dong Kim discloses a system for exchanging lamps of an LCD (see FIGS. 14 and 15). The system 100 includes a liquid crystal panel 13, a frame 12, and a plurality of lamps 17. A plurality of generally rectangular through holes 131 is defined in an upper beam of a frame of the liquid crystal panel 13. A rubber plate 18 is elastically attached on a lateral surface of a head portion of each lamp 17. The lamps 17 are inserted through the through holes 131, and engaged therein by elastic compression of the rubber plates 18 therein. In addition, each through hole 131 is bounded by an inwardly slanting slanted surface 132, so that the lamp 17 is easily inserted into the through hole 131. A connector 171 of the lamp 17 is electrically connected to a power system (not shown). When the lamps 17 are pulled out from through holes 131, the elastic force between the rubber plates 18 and the through holes 131 is released, thereby allowing replacement of the lamps 17.
Even though the system 100 enables exchanging of the lamps 17 of the LCD, the system 100 encounters some problems as follows:
First, the lamps 17 cannot be firmly engaged with the liquid crystal panel 13. According to the system 100 of the patent, the lamps 17 are engaged in the through holes 131 of the liquid crystal panel 13 only by means of the elastic force between the rubber plate 18 and the slanted surface 132 in the through hole 131. The elastic force between the rubber plate 18 and the slanted surface 132 is easily released by vibration or shock. Further, an end 172 of each lamp 17 is not secured, thus rendering the lamps 17 themselves unduly unstable.
Second, each lamp 17 is easily damaged, which can substantially increase the cost of the system 100. The lamps 17 may be removed from the liquid crystal panel 13 if they are damaged or broken due to an accident or wrong operation. In particular, the lamps 17 are liable to sustain shock during transportation of the LCD. In another embodiment of the system 100, a fixing solution using a screw is provided to secure the lamp 17. However, fixing the screw increases manufacturing time and costs. In addition, because the end 172 of each lamp 17 is not stable, there is an unduly high risk of damage to the lamps 17 when they are accidentally displaced from the liquid crystal panel 13. In general, each lamp 17 has a slim body with a small diameter in the range from 2 mm to 3 mm, and the main support of the lamp 17 is a hollow glass tube. Therefore, in manufacturing, the lamp 17 is easily broken when being inserting into or pulled out from the corresponding through hole 131 in oblique directions. In particular, the end 172 of may be broken when the lamp 17 is pressed into the through hole 131. These difficulties reduce the yield of the system 100 when exchanging of lamps 17 of the LCDs is required, which increases costs commensurately.
Third, each lamp 17 must be combined with the corresponding rubber plate 18 prior to installing the lamp 17 in the liquid crystal panel 13. That is, the rubber plate 18 has to be attached on the lateral surface of the head portion of the lamp 17 before attaching the combination in the liquid crystal panel 13. This increases a manufacturing time and costs of the system 100.